Water molecules are bombarded with microwave radiation, which mutates their genetic recipe into any kind of food you want.
8 seconds sound clip from the Cloudy with a Chance of Meatballs movie soundboard.
You can hear this line at 00:23:48 in the Blu-ray version of the movie.
Quote context
[...]
- Right, right. That's why I... I did that. On purpose.
- Right.
- Okay.
- The machine uses a principle of hydro-genetic mutation.
- Yes.
- Yes.
- Peas?
- Steak?
- Yes.
- Apples?
- Mm-hm.
[...]